On the home server of the poll it's 25 vs 3 in favor of being a bit hungry. 😊
The rationale for arriving a bit hungry is easy: You want to optimize intake, for the sake of yourself, the host's honor, or both. If that's not it or incomplete, feel free to enlighten me!
The rationale for arriving a bit full is more subtle. I provided part of one in libranet.de/display/0b6b25a8-1… but would like to hear from others who answered "slightly full":
Which culture are you from, and why is it polite to arrive slightly full?